Patent CA-2919660-A1 (CA)
Inventor: NOTT DARCY STEPHEN
IPC: E21B21/01
Filed: 2014-07-23
Abstract: Apparatus, systems, and methods for continuously circulating drilling fluid through a tubular string are described. The methods include connecting a sub having a central bore and a side bore to the tubular string, connecting a top drive to the tubular string, connecting a manifold to the sub and top drive, wherein the manifold comprises a plurality of electrically controlled valves, and controlling the flow of drilling fluid through the sub and top drive by selectively opening and closing the electrically controlled valves, THE CLAIMS  What is claimed is: 1.    A method for continuously circulating drilling fluid through a tubular string, which method comprises: connecting a sub having a central bore and a side bore to the tubular string;  connecting a top drive to the tubular string; connecting a manifold to the sub and top drive, wherein the manifold comprises a plurality of electrically controlled valves, wherein the plurality of electrically controlled valves consist of a first valve configured to control flow through the central bore, a second valve configured to control pressure through the side bore, a third valve configured to bleed pressure off the central bore, and a fourth valve configured to bleed pressure off the side bore; and controlling the flow of drilling fluid through the sub and top drive by selectively opening and closing the electrically controlled valves. 2.    The method of claim 1, wherein the plurality of electrically controlled valves comprise gate valves, wedge valves, or a combination thereof. 3.    The method of claim 2, further comprising opening the first valve and closing the second valve to allow drilling fluid to enter the side bore and not the central bore, closing the first valve and opening the second valve to allow drilling fluid to enter the central bore and not the side bore, or both. 4.    The method of claim 3, wherein the first and second valves are in an interlocked relationship, the first and third valves are in an interlocked relationship, the second and fourth valves are in an interlocked relationship, the third and fourth valves are in an interlocked relationship, or a combination thereof.     5.    The method of claim 4, further comprising closing the first valve and opening the third valve, opening the first valve and closing the third valve, or both; further comprising closing the second valve and opening the fourth valve, opening the second valve and closing the fourth valve, or both; or a combination thereof. 6.    The method of claim 1, further comprising measuring a position of each of the valves, each of the fluid pressures, or both, in the central and side bores. 7.    The method of claim 6, further comprising displaying the valve position, fluid pressure, or both. 8.    The method of claim 7, further comprising storing past valve position, fluid pressure, or both. 9.    The method of claim 8, further comprising comparing measured valve positions or fluid pressures, or both, relative to a previously measured valve position, fluid pressure, or both. 10.    The method of claim 9, further comprising displaying a warning or sounding an alarm if the measured valve positions or fluid pressures, or both, are substantially different from the past valve positions or fluid pressures, or both. 11.    A manifold for continuously circulating drilling fluid through a tubular string, which comprises: a plurality of electrically controlled valves that control a flow of drilling fluid through a top drive and a sub having a central bore and a side bore, wherein the plurality of electrically controlled valves consist of a first valve configured to control flow through the central bore, a second valve configured to control pressure through the side bore, a third valve configured to bleed pressure off the central bore, and a fourth valve configured to bleed pressure off the side bore; and a controller configured to monitor positions of the valves and fluid pressures at the central bore and side bore.     12.    The manifold of claim 11, wherein the plurality of electrically controlled valves comprise gate valves, wedge valves, or a combination thereof. 13.    The manifold of claim 11 or 12, further comprising an interlock system configured to ensure that the first and second valves, the first and third valves, the second and fourth valves, the third and fourth valves, or any combination of the foregoing, are not open simultaneously. 14.    The manifold of claim 11, 12, or 13, wherein the controller measures the valve positions, fluid pressures, or both, and compares the measured valve positions, fluid pressures, or both, relative to a previously measured valve position or fluid pressure, or both. 15.    The manifold of claim 14, wherein the controller displays a warning or sounds an alarm if the measured valve positions, fluid pressures, or both, are substantially different from the past positions, pressures, or both. 16.    The manifold of any one of claims 11-12 or 13-15, wherein the controller comprises a human-machine interface (HMI) 17.    The manifold of claim 16, wherein the HMI comprises a touch screen interface; wherein the HMI  displays valve position and valve safety interlock information; or both. 18.    The manifold of claim 16 or 17, wherein the controller is integrated into a rig programmable logic controller (PLC) or integrated into an electric actuator. 1 9.    A continuous drilling system comprising: the manifold of claim 11; a tubular string; and